Treatment Phenolic Compounds in Coal Gasification Wastewater by Hydrolytic Acidification-AO Process

2013 ◽  
Vol 807-809 ◽  
pp. 1083-1086 ◽  
Author(s):  
Peng Xu ◽  
Hong Jun Han ◽  
Sheng Yong Jia ◽  
Bao Lin Hou ◽  
Qian Zhao

Using hydrolytic acidification-AO process treating coal gasification wastewater, the COD, total phenols in the effluent and the removal efficiencies were studied. The start-up period was separated to two stages with influent COD concentration of 1500 and 2500mg/L. After 59 days operation, the COD and total phenols removal efficiencies were 80.3% and 72.9%, respectively. The COD and total phenols increased to 925.4 and 238.7mg/L when the HRT was reduced to 6h with the corresponding concentrations of influent were 2512.9 and 493.4mg/L. When the HRT in hydrolytic acidification was reduced to 100%, the removal of total phenols dropped from 75.4% to 57.6%. The bigger circle ratio of 500% didn't have obviously effect on total phenols removal of the process.

2011 ◽  
Vol 347-353 ◽  
pp. 264-268
Author(s):  
Wen Qi Zhang ◽  
Pin Hua Rao

Laboratory and pilot scale experiments indicated that the diatomite additive could improve the stability of activated sludge process and the efficiency of COD removal for coal gasification wastewater treatment. In this paper, the effect of diatomite additive on biomass respiratory activity was studied to investigate the enhancing mechanism. Experimental results showed that diatomite additive could enhance biomass activity obviously when the biomass activity was inhibited by the wastewater with total phenols concentration of 188.9 mg/L -501.2 mg/L. It could be concluded that the mechanism of diatomite enhancing biomass activity were its adsorption of phenols and concentration of DO.


2015 ◽  
Vol 5 (4) ◽  
pp. 569-578 ◽  
Author(s):  
Qian Zhao ◽  
Hongjun Han ◽  
Fang Fang ◽  
Haifeng Zhuang ◽  
Dexin Wang ◽  
...  

Different strategies, including extension of hydraulic retention time (HRT), dilution, and addition of powdered activated carbon (PAC) and super-powdered activated carbon (S-PAC), were investigated for the quick recovery of nitrifying bacteria activity from the inhibition of coal gasification wastewater (CGW). A laboratory-scale short-cut biological nitrogen removal (SBNR) reactor treating CGW, achieving high levels (90%) of nitrogen removal, was used. After a shock of phenolic compounds (around 250 mg/L) and a failed performance, the results of the batch recovery tests indicated that the PAC and S-PAC addition were the best recovery strategies. In the SBNR reactor, the addition of 1 g/L PAC and S-PAC shortened the recovery time from the natural recovery of 32 days to 13 days and 10 days, respectively. Fluorescence in situ hybridization (FISH) assay and the adsorption isotherms revealed that activated carbons absorbed phenolic compounds, reducing the toxicity and allowing for the quick recovery of SBNRs treating CGW. S-PAC showed greater adsorption capacity for phenol than PAC.


2012 ◽  
Vol 568 ◽  
pp. 260-264
Author(s):  
Yan Zhang ◽  
Li Li Wang ◽  
Zheng Yang Yang ◽  
Xu Ying Zhao ◽  
Huan Guang Liu ◽  
...  

In this study, the effect of environment materials for civil engineering was investigated through two sets of parallel reactors with sodium acetate and starch as carbon source separately. The reactors were started up by two stages, including biofilm formation stage and biofilm domestication stage. In biofilm domestication stage, the average removal efficiencies of COD were 88.84% and 88.78% respectively. NH4+-N removal efficiencies were reached at 99.28% and 91.90%. Total nitrogen(TN)removal efficiencies were 45.25% and 45.45%. By PCR-DGGE, it was found that there were high similarities between biofilm and suspension in the reactors. Different types of carbon sources enriched different types of microorganisms. The study can provide references for studying simultaneous nitrification and denitrification(SND)and optimizing carbon sources.


1998 ◽  
Vol 38 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Junxin Liu ◽  
Weiguang Li ◽  
Xiuheng Wang ◽  
Hongyuan Liu ◽  
Baozhen Wang

In this paper, a study of a new process with nitrosofication and denitrosofication for nitrogen removal from coal gasification wastewater is reported. In the process, fibrous carriers were packed in an anoxic tank and an aerobic tank for the attached growth of the denitrifying bacteria and Nitrobacter respectively, and the suspended growth activated sludge was used in an aerobic tank for the growth of Nitrosomonas. A bench scale test has been carried out on the process, and the test results showed that using the process, 25% of the oxygen demand and 40% of the carbon source demand can be saved, and the efficiency of total nitrogen removal can increase over 10% as compared with a traditional process for biological nitrogen removal.


2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.


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